1. Field of the Invention
The present invention relates to an indicator-equipped flow regulating valve which controls the flow rate of a fluid by regulating, for example, the valve opening degree of a valve plug displaced by the pilot air and which makes it possible to visually recognize the opened/closed state of the valve plug.
2. Description of the Related Art
A flow regulating valve has been hitherto adopted to adjust or regulate the opening degree of a valve which is displaceable by the pilot air and to control the flow rate of the fluid flowing through a fluid passage. For example, the flow regulating valve is connected to a fluid pipe through which the fluid flows. In order to confirm the opened/closed state of the valve of the flow regulating valve, a two way valve equipped with an indicator is connected independently to the pipe disposed on the downstream side of the flow regulating valve. The indicator is displaceable in response to the flow rate of the fluid flowing through the pipe.
That is, when the flow regulating valve is in the valve-opened state, then the fluid flowing through the flow regulating valve is supplied to the two way valve connected on the downstream side, and the indicator of the two way valve is displaced by the fluid. Accordingly, the indicator shows that the flow regulating valve is ON, i.e., in the valve-opened state. When the flow regulating valve is in the valve-closed state, the fluid is not supplied to the two way valve connected on the downstream side, because the fluid is blocked in the flow regulating valve. Therefore, the indicator of the two way valve is displaced in a direction opposite to that in the valve-opened state, and the indicator shows that the flow regulating valve is OFF, i.e., in the valve-closed state.
However, the flow regulating valve and the indicator-equipped two way valve are provided independently on the pipe. Therefore, the piping cost for connecting them is increased, and the piping operation is complicated.